148,482 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Forcing, damping and detuning for single and coupled Van der Pol oscillators
No full textWe use Melnikov function techniques together with geometric methods of bifurcation theory to study the interactions of forcing, damping and detuning on resonant periodic orbits for single and coupled forced Van Der Pol oscillators. For a coupled pair the local bifurcation geometry is almost everywhere described in terms of the singularities of a line congruence in three dimensions
Extinction estimation over land ice using long-wavelength Pol-InSAR
No full textIn recent years there has been increased interest in using SAR to study and monitor glaciers and ice sheets for glaciological and climate change research. This paper describes for the first time the estimation of ice extinction through the modelling of Pol-InSAR coherences as a combination of a surface contribution from the snow-ice interface and a volume response. Separation of the ground and volume contributions is obtained through decomposition of the polarimetric coherency matrix. Both model-based Freeman 2- and 3-component and eigenvector decompositions are examined. Ground-to-volume scattering ratios derived from polarimetry are used in conjunction with Pol-InSAR interferometric coherences to invert the extinction of the ice layer. Validation is performed with airborne Pol-InSAR data at L- and P-band collected using DLR's E-SAR system over the Austfonna ice cap in Svalbard, Norway as part of the ICESAR campaign
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
IF analysis of DNA polymerases, Pol δ, Pol α, Pol ε, Pol η, Pol ι, Pol κ, REV1, and Pol ζ, in the cells of HAE-ALI.
No full text<p>HAE-ALI cultures, labeled as “Non-dividing,” were infected with HBoV1 or mock-infected. At 12 dpi, HAE cells trypsinized off the Transwell inserts were analyzed by IF using anti-Pol δ (<b>A</b>), anti-Pol α (<b>B</b>), anti-Pol ε (<b>C</b>), anti-Pol η (<b>D</b>), anti-Pol ι (<b>E</b>), anti-Pol κ (<b>F</b>), anti-Pol Rev1 (<b>G</b>), and anti-Pol ζ (<b>H</b>) antibodies. Primary airway epithelial cells, labeled as “Dividing,” cultured as monolayer in a flask were stained with the above antibodies as antibody positive control. Nuclei were stained with DAPI (blue), and the stained cells were visualized by confocal microscopy at a magnification of ×100.</p
Components of the Pol IV and Pol V holoenzymes in <i>B</i>. <i>distachyon</i>.
No full textComponents of the Pol IV and Pol V holoenzymes in B. distachyon.</p
Los oficiales del Ej??rcito Auxiliar del Per?? y la construcci??n de la carrera de la revoluci??n
No full textEl inicio del proceso revolucionario en el R??o de la Plata lanz?? a la guerra a muchos hombres que se enlistaron en las distintas fuerzas que conformaron los gobiernos revolucionarios entre 1810 y 1820. La extensi??n del conflicto b??lico en tiempo y espacio llev?? a que muchos de estos nuevos ???soldados de la independencia??? pasaran una buena parte de su vida adulta empu??ando las armas en pos de la construcci??n y consolidaci??n de esas nuevas entidades pol??ticas surgidas de las ruinas del Virreinato del R??o de la Plata. Peromuchos de estos hombres, adem??s, vieron en la revoluci??n, la oportunidad de hacer una carrera, una carrera pol??tica
Marilyn B. Skinner (Ed.), A Companion to Catullus, 2007
No full textTordeur Pol. Marilyn B. Skinner (Ed.), A Companion to Catullus, 2007. In: L'antiquité classique, Tome 77, 2008. pp. 423-424
Estimation of glacier ice extinction using long-wavelength airborne Pol-InSAR
No full textIn recent years there has been increased interest in using synthetic aperture radar (SAR) to study and monitor glaciers and ice sheets for glaciological and climate change research. This paper describes the estimation of ice extinctions through modeling of Pol-InSAR (polarimetric interferometric SAR) coherences as a combination of a surface contribution (from the snow-firn interface and wind-induced sastrugi features) and a volume response. Ground-to-volume scattering ratios derived from a novel polarimetric decomposition are used in conjunction with Pol-InSAR coherence magnitudes to invert the extinction of the ice layer. The inversion is performed for experimental airborne Pol-InSAR data at L- and P-band acquired by DLR's E-SAR system over the Austfonna ice cap in Svalbard, Norway as part of the 2007 ICESAR campaign. Extinction-dependencies on frequency and glacier facie
are investigated, and validation is performed comparing ground penetrating radar data to SAR backscatter and extinction values
Ship and Oil-Spill Detection Using the Degree of Polarization in Linear and Hybrid/Compact Dual-Pol SAR
No full textMonitoring and detection of ships and oil spills using
synthetic aperture radar (SAR) have received a considerable attention over the past few years, notably due to the wide area coverage and day and night all-weather capabilities of SAR systems. Among different polarimetric SAR modes, dual-pol SAR data are widely used for monitoring large ocean and coastal areas. The degree of polarization (DoP) is a fundamental quantity characterizing a partially polarized electromagnetic field, with significantly less computational complexity, readily adaptable for on-board implementation, compared with other well-known polarimetric discriminators. The performance of the DoP is studied for joint ship and oil-spill detection under different polarizations in hybrid/compact and linear dual-pol SAR imagery. Experiments are performed on RADARSAT-2 -band polarimetric data sets, over San Francisco Bay, and -band NASA/JPL UAVSAR data, covering the Deepwater Horizon oil spill in the Gulf of Mexico
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